If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You will be required to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.

How best to edge glue 3/4" oak boards

03-09-2009, 09:22 PM

I'm working on one of my bigger projects, a dining room table for my daughter out of 3/4"oak. To make the table top I have to edge glue eight 3/4"X 7" boards together and I'm thinking that glue alone my not be strong enough. Also I'm concerned that I may not be able to align them just perfectly when gluing them so as to have a reasonably level joints. Would incorporating the use of dowels be something I should be considering, I was also thinking about biscuits although I've never used them. If anyone has any suggestions on how I should proceed I'd love to hear from you. Thanks
By the way the oak boards are already S4S so pretty well finished smooth.

I am inferring that you mean 7' not 7" long. That is a lot of boards to be fiddling with at one time. I would probably do it in at least two and maybe three glue-ups then glue everything together. If I did it in three sections I would glue two together and then add the third later.

I read, I think in, 'The 250 Best Shop Tricks,' a supplement to 'Woodworkers Journal' of a guy who plowed a 3/4" grove in a couple 2x4s and slid them over the ends of his glue-up to align the ends. Pretty good idea, might work for you.

I have a biscuit cutter so I would probably use it to help with alignment but it isn't necessary, unless of course you are in the market for another tool.

By all accounts, everything I have read, indicates that wood glue is stronger than wood, so the addition of biscuits would be primarily for alignment, not strength.

If you can enlist the help of someone to help with the glue-up that would help a lot. Seven feet is a lot of board.

Comment

Edge gluing will be plenty strong if you use one of the leading brands of wood glue. Titebond III is great and the strength is in the area of a couple thousand pounds. In fact the glue line, if properly applied, will end up being stronger than wood itself. I still have a small maple table I made over 15 years ago. I made it of two 8" boards glued together. Nothing fancy. Actually pretty lame and I did the edge were "jointing" on a cheap table saw using a cheap HSS blade, and I made burn marks too. The point is that the table top is still very strong.

You are correct that for aligning the boards you could use biscuits or dowels, with the latter providing a stronger joint. My personal preference is for dowels with the use of one of a dowel jig. I bought a self centering one ($40) but I'm now seriously considering Joint-Genie as it appears to offer more flexibility.

In order to understand recursion, one must first understand recursion.

Comment

How do you plan to treat the ends of the table top? There will be a lot of end grain there to deal with. Will you breadboard the ends or some other treatment? May have to re-think construction and assembly methods.

You could if you don't have a biscuit joiner use dowels or you could spline them, but this would mean you would have to do something with the ends.

If you use dowels be sure to index everything from the same side. Build a simple drilling jig, an L shaped piece with a guide hole spaced the right distance from the edge, to ensure your holes will line up. This will help keep the face of the boards aligned.

Comment

A very effective way to join that many pieces would be to utilize a spline joint. It will give you an incredibly strong joint and last for years to come. I've also used biscuits to join pieces as the biscuits absorb the glue swell, make a strong joint and provide a permanent bonding point. Either way, I would think that you would need something to supplement the 5 foot length. So the choice is a biscuit joiner or router and table.

Comment

Thanks all for the suggestions, I will certainly invest in making some cauls as when gluing the boards together the entire table top will be almost 58 inches wide. As for the ends of table where the end grain is I had planned on putting in a breadboard 2-3" wide using a spline along most of the length. Will also look for the Titebond glue as I hadn't thought of the type of glue to use.

Comment

I know I am a little late to the party here, but I would suggest briskets, (I have less luck with dowels), I would clamp from the bottom as well as the top, (it keep tension on the glue up even and keeps it from bowing or helps) I would use a jointer to get the edges as straight as possible first, I would find as flat as a surface as possible to work off of,

I would be some what concerned about the possible cross gain end attachment, If any thing build up the edges with a double piece if you want some depth, but by going cross grain on the ends, if the wood shrinks you may end up with a split clear thought the table, Oak changes a lot with humidity,
I made a leaf for a table one time (this was out of construction grade lumber) but since the table was the same out of 2x6's I glued up a 3' x 3' piece for the table, and about two weeks later there was this loud crack sound and the piece had basically reduced it self into three pieces,there were two ribs under the leaf to keep "from splitting it" it end up causing it to split,

if a cross grain piece is used on a large panel it should be designed to float so the other wood can expand and contract, (why it is suggested not to glue the panels into a rail and stile door,

Push sticks/blocks Save Fingers
~~~~~~~~~~~~~~~~~~~
"The true measure of a man is how he treats someone who can do him absolutely no good."
attributed to Samuel Johnson
~~~~~~~~~~~~~~~~~~~
PUBLIC NOTICE: Due to recent budget cuts, the rising cost of electricity, gas, and oil...plus the current state of the economy............the light at the end of the tunnel, has been turned off.